(112. MESSRS. E. HERON-ALLENf AND A. EARLAND ON 
coarse perforations, like the rose of a watoring-can. Where this oral layer, 
which closely resembles the inaroinal edge of Orhitolites complanata, has 
heeii broken away at a point on the edge, a similar cribrate septum is visible 
underneath. 
The specimen bears a superficial resemblance to the Mycetozoan genus 
Craterium . 
The genus represents a morphological variation of the normal structure of 
Orhitolites complanata. In that type the chamberlets form a disc, the sides 
of which are imperforate, while the edge of the disc is covered with cribrate 
apertures. In Craterites the disc is originally perforate on one side and 
imperforate round the edge. Growth ensues by the addition of a series of 
chambers, which must necessarily be superimposed over the aperture. Hence 
we get a series of discs superimposed on one another and with a circular cribrate 
covering over all in Craterites, while in Orhitolites the original disc increases 
rapidly in diameter by the addition of rings of concentric chamberlets. 
Size :— 
Height from edge of base to top of cover, 1"20 mm. 
,, „ bottom of cover, "70 mm. 
Diameter at base, '95 mm. 
,, narrowest part of trunk, '55 mm. 
„ widest part of trunk and junction of cover, '95 mm. 
Alvbolina d'Orhiciiiy. 
58. Alveolina melo (Fichtel t^- Moll). 
Nautilus melo Fichtel & Moll, 1798, TM. p. 118, pi. 24. 
Alveolina „ Heron- Allen & Earland, 1914-15, FKA. p. 607. 
A single large specimen. 
Family ASTROKHIZIDJi:. 
Sub-family Astrorhizin/E. 
Iridia Heron-Allen S,- Earland. 
59. Iridia diaphana Heron-Allen Sf Earland. 
Iridia d.iaplia:ia Heron-Allen k Earlnnd, 1914-15, FKA. 1914, p. .371, pi. 36 ; 
1915, p. 607. 
The species is evidently abundantly attached to coral and nullipore 
fragments. Several good specimens were obtained, both sessile and detached, 
the latter exhibiting the dried protoplasmic body beneath the chitinous 
membrane, 
